Lunacy
by Grim Demise
Summary: [A role-reversal AU but with a sweet, sweet twist because that's how I like it.] Tadashi finally brought down the Yokai, the one responsible for Hiro's death. But he didn't expect what's hidden behind the mask, now he's torn choosing two different choices. Defeat the 'Yokai' or give up to protect others.
1. Chapter 1

_[New story and this has been in my mind for several of days thus I finally get to make it. I love this AU, my favorite AU, an AU I made up in my head, other people might hate but I love it personally. Please have mercy upon me if you finish reading this….]_

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><p>He will kill him….<p>

Tadashi will kill that person who took his little brother away. The person who started the fire while Hiro was still inside the hall, trapped inside the inferno that burnt his existence into ashes.

Hiro was his everything. Hiro inspired him to help many people, created Baymax and a whole lot more. He created the microbots thanks to Tadashi's motive. He could have been happier with him when he finally accepted into some 'nerd college' that he finds it spectacular now. They have a whole new life ahead of them….

But no, instead of a happy life, someone started the fire, stole the microbots and resulted in Hiro's death when there was an explosion that cuts off Tadahi's chance to rescue his little brother. His creation was tainted in the hands of a criminal…. And he will take him down, one way or another.

"Guys, right there! Get him, Gogo!" Tadashi commended. Gogo threw her right disc right at the masked individual, hits him in the head as he fell off the pile of microbots and his mask, miraculously, was removed.

The team was breathless, spent hours trying to take the masked-individual down but they finally did it, now they're going to know who stole the microbots and for what purpose. They were all pending on Alistair Krei behind the mask, since he wanted Hiro's microbots and almost stole one if it wasn't for Tadashi, but they're still uncertain. But they wouldn't have to wait anymore; the criminal is right now in front of him, defenseless.

Tadashi, being the leader of the team, was the first on to step forward along with Baymax. For some reason, Baymax stopped when Tadashi is only a few meters away from their target. Tadashi was confused by the robot's sudden halt, "Baymax, what's wrong?"

"Tadashi, Hiro is here." Baymax told him.

However, Tadashi doesn't want to hear that, over and over again for the past few days. He gritted his teeth as he exclaimed, "Hiro is NOT here, Baymax. It's just his microbots…. And his killer….." _I will soon avenge him…._

"But Tadashi-"

"Not NOW, Baymax."

The once masked-person was finally on his feet, clutching his right arm. Now that Tadashi realized, the target looks small, too small to be an adult. He can scratch Krei's name off the list for being the suspect but…. Who on earth wants his brother's microbots then?

As he turned around to face the team, Tadashi once filled with wrath was replaced with the cold-feeling dread. His breath hitched as he can't make out the words he's trying to get it out. The other team, Gogo, Honey Lemon, Wasabi and Fred, they have the same reaction and feelings going on in their head; rage, betrayed and…. fear.

Only Baymax doesn't seem to bother, "Hello, Hiro."

The masked individual, the person they all have been chasing after and the culprit who's controlling the microbots was the creator himself, Hiro Hamada.

"Hiro….?' Tadashi muttered; he couldn't believe his eyes. His little brother standing there, alive and well. He watched his little brother buried with his urn yet Hiro is still there all in one piece; save for the burnt left side of his face. He suffered the guilt that's consuming him every day after the funeral and only to find out now Hiro is still alive all this time. His emotions were messed up right in this moment, and first one to come up was distrust. "How…"

Hiro chuckled, not the childish one but rather menacing one, that wasn't like him at all. "Oh, do you think a simple fire could kill me, _nii-san?_"

He hasn't call him that for years now, Tadashi would be glad if it wasn't for the dark look engraved on his brother's face, he was horrified. _What happened to him!? This isn't the Hiro I know!_

Gogo stepped up and glared right at him, scowling, "Hiro Hamada, what's the meaning of this? And why are you trying to run away or more importantly,_kill _us few days ago?"

"The meaning of the whole thing, Gogo?" Hiro laughed, a crazed one. "Why, isn't obvious? Or are you all too blind & stupid to see what actually happened during the fire?"

Hiro glanced at Tadashi; a small fond smile appeared on his face, "Oh nii-san, you were always there for me. You always say you always have my back, no matter what. And I always felt safe because of those promises of yours." Immediately, his smile turn into a scowl and his voice sounds threatening, "_**But where the hell were you when I needed you the most?"**_

"I thought you were dead!" Tadashi yelled. "That explosion, Hiro, you couldn't have survived that explosion-"

"Stupid, stupid, stupid!" Hiro growled. "I had my microbots, I shielded myself with it, and even people like you all should know that! Unless, of course, I didn't do it on time if it weren't for that professor….."

"Professor Callaghan…?" Honey Lemon guessed, earning a smirk from Hiro. "W-What happened to him…? You…. did save him too…. Did you?"

"I have no intention to save _**a thief**_…." Hiro hissed. "He started it all, the fire mostly. He's the one you should all blame for ruining your 'nerd school'. He tried to steal my microbots; he tried to kill me… _**But, I wouldn't want any of that to happen **_so I did what he could have done to me when he had the chance…."

"You killed him….." Tadashi said in disbelief. "Why…. Hiro, why!?"

Hiro sighed, has a hurtful look on his face, "You said you don't want bad things happened to me and neither do I, and so I did what you always told me to; fight back. It's not _**my fault**_ he tried to steal my own invention and certainly not mine as well that he wanted to _**get rid of me**_. So why do I bother to let him out _**alive**_?"

A wide grin spread across his face, "And you, nii-san, you know while I'm in that burning building, shielded by my own microbots, as seconds and minutes passed _**I waited in agony**_ for you to come to my safety. Telling me 'it's okay' and everything would be alright? _**Do you know how hurt I am when you didn't come AT ALL?"**_

A swarm of microbots suddenly surrounded the team and trapped them as they struggled to break free; the extras surrounded Hiro instead, "The only thing the fire gotten rid of was that professor…. And that precious _kid _you guys used to know…."

"The microbots!" Fred panicked. "Dude! I thought we gotten the transmitter behind that mask off of him!"

Hiro laughed, stepping forward as the other microbots followed him, behind their creator and forming a wall as Hiro devilishly smirked, "Do you really think I'm stupid? I knew you guys would have the idea of removing my mask that you guys _**think **_hid the transmitter, I wouldn't have the control anymore? I'm always one step ahead of you all, I'm always prepared the simplest of all things. The transmitter is no longer a headband or behind a mask to simply wear, instead the transmitter is….."

He pointed at his head, immediately the gesture hinted clicked in everyone's head as they were confounded and wouldn't believe their youngest friend would go so far. However, Hiro just laughed at their shocked expression as he exclaimed, "That's right! The transmitter is now a chip located…. _**inside my head. **_Now, not only I control them with my thoughts, I can control them with my emotions! Now, I'm feeling a bit of weary dealing with you guys right now…."

Hiro raised his left hand and the stance of the remaining microbots went higher and higher forming a wave-like structure. He used right hand to commend the other remains to lift him up, standing above and looking down at them like a superior. He grins evilly and said, "Good riddance…." And instantly dropped his left hand as the microbots' comes crashing down.

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><p><em>[Ayyy, Yokai or Evil Hiro is my favorite kind of hero (this is not a pun, I'm being completely serious right now). And like I said from the top reminder of this story, please have mercy upon me as I made Hiro going against his brother and others. Of course, I won't lose focus on this story so it's not going to be a simple one-shot! So, heads up for newest updates! (Plus the next chapter is actually a filler so heads up for other actual important updates!).]<em>


	2. Chapter 2

_[I WENT ON A VACATION FOR A FEW DAYS AND I'M SORRY FOR NOT TELLING YOU GUYS THAT AND I KNOW YOU GUYS WERE WAITING FOR THE NEXT CHAPTER so here it is, the filler chapter, enjoy ( - v-)/]_

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><p><strong><span><em>[Hiro's P.O.V]<em>**

'_Tadashi will rescue me….I'm sure…!'_

_I thought desperately as the microbots took a form of a sphere around me to shield myself from the fire. The fire was intense and I couldn't go any further without coughing every time I inhaled the smoke, I don't even know if I was going the right way out! I'm…. stuck…..lost. _

_How did it end up like this? I….. I was just going to get the neurotransmitter back from the stage and- and that professor stole it from me and set the fire….near where I lied when he pushed me away harshly. _

_It hurts…._

_My face hurts….._

_My left eyesight became….. extremely vague._

_But I have to stop the professor from stealing my microbots….so I pushed him into the fire and watched him burn. His piercing screams….. keep on repeating my mind. I put on the neurotransmitter and with many thoughts running in my mind, the microbots scattered around in catastrophic manner. My thoughts that time were…._

'_**Save the professor!**__' '__**Leave him to be burn alive!**__' _

'_**Find Tadashi!**__' '__**Save yourself from the fire!**__'_

'_**Destroy everything in your way to find the exit!**__'_

'_**Wait for others to come!**__'_

_**I was completely torn….**_

_I…..ended up killing the professor because of it and…save myself from the fire without going anywhere and that's when I became so dependent on my microbots. At the same time, I was thinking about my brother. I left him when I said I'm going to get my invention….. Is he still waiting by the bridge? Did he not realize what's going on right now?_

_Did he…left with the others…..?_

_No….. No, no, no, he couldn't just leave me here. I'm sure he knew something went wrong. He has waited long enough to realize that. Or maybe….he actually left without bothering….. thinking I might actually be fine on my own…. Just myself here… __**alone.**_

'_He's always there to protect me….. He wouldn't do that!'_

_Because of that, the thought of keeping myself safe was shattered as the microbots starts to break down its wall. I panicked and tried to reform the structure but I keep on thinking of Tadashi and his absence. 'Why is he not here yet?! What took him so long?! Maybe, he couldn't see through the smoke or- or the path blocked that he couldn't search any further or-?!'_

_I couldn't focus…. All these thoughts start to pile up and eventually, I lost control of my microbots as they shattered to the ground. I began to hyperventilate; __**I'm going to die alone**__. Nobody is coming, __**especially Tadashi**__. He's nowhere; he's not going to rescue me this time….. like what he promised if ever went bot-fighting or did something wrong again. _

_**He left me here to die.**_

_I screamed and my harsh thoughts accidentally triggered the microbots whipped around and destroying the beams of the building to fall apart and collapsed as the flame engulfed the remains and began spreading more. My mind went blank when I watch the fire slowly sway around me. Eventually, I left that place with my microbots, __**by myself**__, not going to where the others were…because…._

_**It doesn't**__…__**matter**__…..__**anymore**__. __**It doesn't matter anymore**_

**__**It doesn't matter anymore._**It doesn't matter anymore._**It doesn't matter anymore._**It doesn't matter anymore._**It doesn't matter anymore._**It doesn't matter anymore.**_**_**_**_**_**_  
><em>**

_**THEY. ALL. LEFT. ME. TO. DIE.**_

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><p><span><strong><em>[Third Person P.O.V]<em>**

Hiro managed to escape through the institute without being seen and into the shady parts of San Fransokyo, where he found an abandoned warehouse; a perfect place to isolate himself from the world.

As the doors shut close behind him and the inside of the warehouse, his microbots quickly dispersed as he took of the neurotransmitter and just stares at it, inexpressive. After a moment, he gritted his teeth as he threw the neurotransmitter to the ground and stepped on it repeatedly out of anger. Looking down to see what's left of his invention, he picked up the chip that's responsible for reading the user's mind.

His blank face starts to break down as he laughed; a distraught idea just crossed his broken mind, _**"Oh, they're gonna have to kill me for this….."**_

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><p><em>[It's short I know because it's a filler chapter after all. Just have to add this because of reasons *shrugs*. If you think I add the 'have' as a mistake (because wow, I have a lot of mistakes here and there. Sorry about that, guys but I'm too lazy to fix that.) well no, not a mistake at all. Plus, I have a really great ending for this story and I can assure it will be a very sweet, <em>_**sweet ending**__…..]_


	3. Chapter 3

_**[**__I literally still have no excuse for why am I late updating this fic, I'm so sorry.__**]**_

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><p>'<em>-dashi...! Tadashi! TADASHI, WAKE UP!'<em>

Tadashi groaned as he slightly opened his eyes; almost regret it when there's a bright light that almost blinded him. He tried to push himself upwards using his elbows, Honey Lemon crouching next to him with a really anxious look plastered on her face, "W-What happened….?"

"Oh, Tadashi…." Honey Lemon cried in relief. "… Tadashi….. Hiro-"

By just hearing his 'supposing-deceased' brother's name, he remembered almost immediately what happened before he passed out, "HIRO! Where did he-!?"

"He left….. Unfortunately with nothing behind…." Gogo answered him, with a displeasing look on her face. "Kid got away when he had the chance obviously…."

With all his strength, he tried to set upright without any struggle and ignoring the pain began to ache badly, somehow. But before he could even make a step forward, Gogo stopped him with a glare and her hand on his chest, "_Hamada_, I know what you're thinking…."

"We have to…." Somehow his voice sounded raspy. "We have to find him…! We have to get him back and get rid of this mess he's in-"

"He tried to kill us without any hesitation!" Gogo shouted at him. "It's easy for you to say as an older brother but to us, it's impossible! He has his microbots and what we have is just you and Baymax! He can easily destroy us!"

"We have to try somehow!" Tadashi exclaimed. "And Hiro….. Hiro is not the type to even hurt anyone."

"Really, Tadashi?" Gogo scoffed. "Then what he did just now was what? A kiddy play that you brothers always fool around during those childhood days? Or some kind of a friendly sibling fights**? That was straight-up manslaughter and Hiro just laughed at us**."

"GOGO!" Wasabi pulled her back to stop the heated argument but it looks like she hasn't given up yet talking some sense into the older Hamada. "That's enough!"

"You brother has changed, Tadashi. He changed too much and now he's not the Hiro you always knew. He's gone, Tadashi, the fire took away that part of him…."

With only silence being in the air, the group nervously closed in around Gogo and not dare to stand near Tadashi, shaking and his fists curled tightly. It's like he's restraining to attack one of them. Except for Baymax, who stood near his creator, voice listing out how his brain activity is running rather awry.

"So, what? Was it my fault?" Tadashi looked straight at Gogo with teary eyes. "Was it my fault that I didn't save Hiro in time?! Was it my fault that I let him go without knowing what going to happen?! _**Was it my fault that I didn't go into that building even when you guys holding me back!?**_"

Gogo didn't reply, just coldly staring at him. The one thing that made Tadashi couldn't tolerate with her all the time, "It's not mine, right? That's what you're telling me always back then…. Again and again and again, until I'm tired of hearing it….. If it wasn't mine, then who is it? _**Who should I blame, Gogo?! Tell me!**_"

The other three flinched when Tadashi yelled; it's always a rare thing for them to see Tadashi really livid and it scared them to no ends. But still with no fright or anything, Gogo simply replied, "You could blame Professor Callaghan. He's the one who started it in the first place, stole the microbots and covering his tracks by setting the building on fire. But he's dead now, isn't he?"

Tadashi just frowned and shook his head, "So there's no one else I should place the blame on, then? It's not mine, not you guys and not even our professor even with all the evidence pointing right at him… _**Are you telling me it's Hiro's own fault?**_"

"You're the one with medical the knowledge, Hamada…." Gogo replied. "You should know what breaks the gentle mind in a horrendous situation…."

_Fear, anger and misery. Just like Tadashi himself right now and weeks ago, when he thought Hiro was gone for good. Is Gogo telling him what Tadashi felt back then, was what Hiro is suffering right now? Was it out of fear Hiro decided to attack them with no mercy? Was it out of anger Hiro killed Callaghan and almost them as well because no one come to his rescue during the fire? And was it out of misery, he's trying to avoid the pain he endured…. Hiro tries to get over it and the only thing he can rely on is his microbots. _

_His microbots now can be controlled by his emotions, was it because of those three things he acted like that? _

"….It wasn't his intention…." Tadashi has to make it clear to his friends. "He didn't mean anything; he didn't mean to kill our professor. He was just-"

"Too terrified?" Gogo finished his sentence. "Hiro could have saved himself if he never put his all his thoughts into his microbots. Just because it can do almost everything, it doesn't mean it can save him from that fire and keeping him alive at the same time….."

_And that's what breaks his mind then, a desperate act and torn with other decisions he could have chosen. _Tadashi thought. It could be, maybe, Hiro….. is only a kid. He's a kid with a big brain and all but that didn't make him invincible at all. He's just like Tadashi, just a softie with a kind heart still even with his cocky personality. His mind overwhelms everything which made him forgets he's just a mortal with a short life. He used his brains for brawns when he does bot-fights, and creating those microbots.

_He's really dependent on his thoughts… If he ever approaches him for the second time, he would- _

Tadashi turned to face Baymax, "Baymax, wings". Immediately, Baymax activated his wings without anything to say. "Tadashi…?" Fred slowly approached the male, almost jumped back when Tadashi replied. "Everyone, get on Baymax's back. We're going home…."

"What about Hiro?" Honey Lemon asked worryingly, maybe it's wrong for her to ask after _that _but Tadashi would never abandoned Hiro in dangerous situation. But would he now?

Tadashi just sighed and replied without facing them, "That….. could wait. I need some time….."

_To what? _Honey Lemon dared to ask but never had the heart to spoke it out loud. It could mean several things why he needed it, maybe to think of plan? Or to calm down first before facing his little brother again? Who knows, things can be pretty unpredictable to them.

The journey back to San Fransokyo from the Akuma Island was silent, and no one dared to break it.


End file.
